Pre-works Road Condition Survey of Derwent Lane Howden Micro Hydropower Project

OVERVIEW/COMMENT ON RESULTS OF SURVEY

Overall, the inspected length of Derwent Lane from the A57 to the Roundabout at the Visitors center appears to be in reasonable structural condition. However there are several areas of Rutting and Surface Fretting which are shown in the schedule.

From the Roundabout continuing along Derwent Lane to the Bridge the road is of a poorer condition. There is amongst other deformities an abundance of Haunch Erosion due mainly to this being a single track road with no edge support and used by agricultural machinery.

There are some random areas of carriageway patching, irregular reinstatement and potholing (large and small) which are noted and their respective location and condition are shown.

Surface water drainage appears to be good although there are a couple of areas where ponding is evident. DESCRIPTION OF TYPICAL DEFECTS IDENTIFIED & ASSESSED DURING ROAD CONDITION

SURVEY OF DERWENT LANE

A. Surface Fretting/Loss of Surface Dressing Chippings 'Fretting' - a common occurrence, due either to ageing and embrittlement of the bituminous binder, leading initially to loss of fine aggregate, or loss of surface dressing chippings through traction by vehicles, particularly at junctions and around bends. Lack of embedment in the early life of a surface dressing can also result in loss of chippings, particularly during cold weather. Fretted surfaces have an open rugous appearance and remain damp longer than sealed surfaces after rain. Progression of fretting can lead to formation of potholes.

B. Wheeltracking/flutting The formation of longitudinal surface depressions in the wheel tracks, caused by the deformation of unstable/bitumen-rich surfacing material subjected to repeated trafficking (channelisation) by vehicles. If accompanied by extensive cracking and crazing this defect may also indicate structural distress in the underlying road base/foundation.

C. ‘Pushing’ of Surfacing Layers Similar causes as rutting, but usually along the inside edge of wheel tracks, particularly around an outside bend and on the braking approaches to junctions. In extreme cases, the bitumen bound surfacing material can ride up the face of an adjoining kerbline.

D. Haunch Erosion/Deformation. In the absence of edge support (kerbs or hard shoulder construction), pavement haunches or shoulders, are vulnerable to settlement and structural damage, i.e. cracking, crazing, erosion, rutting and general deformation from overrunning heavy vehicles. This is particularly noticeable on the inside of bends, and in the vicinity of ditches and where no positive drainage or edge support exists.

E. Potholes These are relatively small holes in a road surface caused by the loss of aggregate from the bitumen bound matrix. Formation of potholes in an aging surface is accelerated by ingress of water and freezing conditions. Whilst the initial depth of a pothole will usually be limited to the thickness of the surfacing course, if the deterioration is not remedied by patching, the depth and overall size will continue to increase, particularly under adverse weather conditions and heavy traffic.

F. Patched/Reinstated Road Surfaces Whilst such repairs properly address weaknesses and defects in existing surfaces, and in some cases the underlying layers and foundations, and lessen the likelihood of further deterioration, any cutting through pavement layers interrupts the structural continuity of the pavement structure, thereby weakening it.

## SCHEDULE FOR THE PREWORKS ROAD CONDITION SURVEY FOR DERWENT LANE

**Sheet 1 of 2**

| Photo Number | Chainage (m) | Position in Road (Nearside=Res side) | Description/Defects/Notes | |--------------|--------------|--------------------------------------|---------------------------| | Start at A57 White Lines as Zero | | | | | 1 | 5.0 – 21.1 | Central (C) | Fretting along the center of road near to overbanding | | 2 | 92.9 | Nearside (N) | Sunken area and Patch repair near Gully | | | 108.6 | | Cattle grid | | 3 | 110.9 | N | Sunken area and Patch repair near Gully | | 4 | 409.9 | N | Cracking and Fretting on old repair | | 5,6,7 | 488.9 – 650.1| N | Surface Fretting/Loss of Surface Chippings | | 8 | 642.2 | C | Potholes | | 9 | 1264.6 | N | Sunken area and Patch repair near Gully | | 10 | 1347.7 | N | Sunken Deformation and Cracking | | 11 | 1522.5 | N | Sunken Deformation (already marked for repair) | | 12 | 1559.8 | N | Fretting around Gully | | 13 | 1762.3 | N | Loss of surface dressing for 10m | | 14 | 1826.8 | N | Loss of surface dressing | | 15 | 1848.3 | N | Loss of surface dressing | | 16 | 1924.7 | N | Sunken area and Patch repair near Gully | | 17 | 1940.6 | N | Loss of surface dressing for 10m | | | 2138.7 | | Derwent Monument | | | 2430.8 | | Cattle grid | | 18 | 2800.7 | N | Pothole next to Gully | | 19 | 2914.7 – 2963.9| N | Loss of surface dressing | | 20,21,22 | 3058.3 | N | Potholes | | 23,24,25 | 3086.3 – 3106.7| N | Potholes | | 26 | 3135.6 | N | Pothole | | 27 | 3180.5 | N | Pothole | | 28 | 3188.8 | N | Pothole | | 29 | 3201.1 | N | Loss of surface area near Gully | | 30 | 3237.9 | N | Old Repair areas showing start of material loss | | 31 | 3266.8 | N | Old Repair areas showing start of material loss | | 32 | 3290.3 | N | Pothole | | 33 | 3333.7 | Offside (O) | Sinking to MH Cover | | Photo Number | Chainage (m) | Position in Road (Nearside=Res side) | Description/Defects/Notes | |--------------|-------------|-------------------------------------|--------------------------| | 34 | 3343.6 | N | Pothole | | 35 | 3348.5 | N | Sunken area and Patch repair near Gully | | 36 | 3359.1 | N | Sunken area and Patch repair near Gully | | 37 | 3392.8 | N | Sunken area and Patch repair near Gully | | 38 | 3533 | N | Pothole | | 39 | 3641.4 | N | Humped area with Fretting | | 40 | 3726 | N | Sunken area and Patch repair near Gully | | 41,42,43,44 | 3726.5 -- 3788.9 | | Various Cracking, fretting and Deformation to the road towards the Roundabout | | 45 | | | Cracking at Roundabout | | 46 | | | Pothole at Roundabout | | | 3843.9 | | Gate |

Starting at the Gate at the Roundabout as Zero

| Photo Number | Chainage (m) | Position in Road (Nearside=Res side) | Description/Defects/Notes | |--------------|-------------|-------------------------------------|--------------------------| | 47 - 54 | 0 - 175 | | Poor surface from the Gate with Various Cracking, fretting and Deformation | | 55,56 | 177 | | 2No Gullies with Potholes and sunken areas | | 57 | 204 – 220.3 | C | Potholes | | 58,59 | 231.9 | O | Sunken area and Patch repair near Gully | | 60 | 238 | | Fretting to large area at the Bridge | | 61 | 432 | O | Ponding at the Path Crossing (old Repair) | | 62 | 454.8 | C | Haunch Erosion/Deformation | | 63 | 461.2 | O | Fretting | | 64 | 493.9 – 506.1 | | Old repair Rutting | | 65 | 626.3 | N | Old repair trench has cracking, Haunch Erosion/Deformation | | 66 | | | Old patch not over banded | | 67,68,69,70 | 656.7 | | Various Cracking, fretting and Deformation to the road towards the Junction to Derwent Dam | | 71 | 726.2 | N | Old patch with surface loss | | 72 | 744 | | Worn trench repair | | 73 | 749 | O | Standing water to offside edge | | 74,75 | 757.2 – 781.7 | | Haunch Erosion/Deformation | | 76 | 804.5 | O | BT Manhole cover with erosion to edge | | 77 | 815.1 | C | Surface loss around old trench | | 78 | 820.8 | N | Surface loss around old trench | | 79 | 823.5 | N | Surface loss around old trench | | Photo Number | Chainage (m) | Position in Road (Near side=Res side) | Description/Defects/Notes | |--------------|--------------|--------------------------------------|---------------------------| | 80,81,82 | 911.2 – 929.8| O,N | Potholes to Farm entrance and sunken areas | | 83,84 | 984.5 | N | Various Cracking, Fretting, Haunch Erosion/Deformation at Telegraph pole | | 85,86 | 997 | O,N | Various Cracking, Fretting, Haunch Erosion/Deformation | | 87 | 1026.4 | | Hump and Fretting | | 88 | 1033.4 | O | Tarmac loss around old trench | | 89,90 | 1053 – 1070.7| O | Haunch Erosion/Deformation | | 91 | 1077.5 | O | Haunch Erosion/Deformation | | 92,93 | 1100.7 – 1151.7| | Fretting/Loss of surface dressing | | 94 | 1169.2 | O | Haunch Erosion/Deformation | | 95,96,97 | 1187 – 1240.5| | Cracking, Fretting, Haunch Erosion/Deformation | | 98 | 1338.8 | N | Haunch Erosion/Deformation | | 99,100 | 1388.6 | | Various Cracking, Fretting, Haunch Erosion/Deformation at Bend | | 101 | 1426.9 | O | Pothole | | 102 | 1451.7 – 1467.9| | Haunch Erosion/Deformation | | 103 | 1555.8 – 1565.6| | Fretting | | 104 | 1638.5 | N | Fretting to new Trench | | 105 | 1677 | N | Fretting to new Trench | | 106 | 1732.8 – 1741.4| | Potholes with old spray marks around | | 107 | 1759.1 | N | Pothole | | 108,109,110 | 1764 – 1804.6| | Various Cracking, Fretting, Haunch Erosion/Deformation | | 111 | 1818.9 | N | Pothole | | 112 | 1836.3 | N | Haunch Erosion/Deformation | | 113 | 1889.8 | O,N | Cracking, Haunch Erosion/Deformation | | 114 - 117 | 1890.3 – 1953| | Fretting and Rutting | | | 1953 | | End of Tarmac |

Start at the Junction towards Derwent Dam as Zero

| Photo Number | Chainage (m) | Position in Road (Near side=Res side) | Description/Defects/Notes | |--------------|--------------|--------------------------------------|---------------------------| | 118 | 74.7 | C | 2 small fretting areas | | 119 | 370 | | Hump in Road | | 120 | 414 | O | Pothole to edge of road at the entrance to the house | | | 436.8 | | End at the Gate at the House |